Hardinge HNC retrofit and where to start

JR1050 wrote:

You would be WAY ahead of the game to buy some inexpensive encoders

I had imagined that the resolvers were more tightly integrated into the motors than appears to be the case. My servos have them inside the back of the case, and I would be looking at trying to source new connector inserts ($20 + the pins each) or the pin-removal tool ($100s) to change the wiring to suit encoders. I would also need to find some form of commutating encoder too, as mine are AC servos reliant on the absolute feedback that resolvers give.

FWIW the Mesa 7i49 Resolver driver emulates the encoder index behaviour, so if the Resolver is a one-cycle-per-rev type (less than certain) then it would be usable for all the normal LinuxCNC spindle encoder things.

It's moderately easy to tell how many cycles-per-rev the resolver is. Power up the drives and put a multimeter in the AC range on one of the secondaries, then rotate the spindle. If you see the amplitude drop to zero more than once a rev then you would need to wire up a separate index or change it to an ABZ encoder.